Internal-combustion engine.



C. S. SALFELD.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED wuss. 1914.

1,267,4 Pafiepted May.28,19

lV/TNESSES:

ante.

CHARLES S. SALFELD, OF MILWAUKEE, WISCONSIN.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented May 28, 3918.

Application filed June 8, 1914. Serial No. 843,777.

To all whom it may concern:

Be it known that I, CHARLES S. SALFELD, a German citizen, residing at 274 Tenth street, Milwaukee, county of Milwaukee, and State of Wisconsin, have invented new and useful Improvements in Internal-Combustion En es, of which the following is a specification.

My invention relates to internal combustion engines in which liquid fuel is injected in to the combustion chamber.

The primary object of my invention is to provide for the best fuel economy obtainable with simple means without the noisy operation and expensive equipment frequently associated with high economy.

A further object of my invention is to provide a cup or hot bulb that is reversibly carried by the piston by which high economy is obtained.

In the drawings:

Figure 1 is a longitudinal section through the combustion chamber of an internal com bustion engine constructed in accordance with this invention.

Fig. 2 is a similarview showing the'same invention in slightly modified form.

Like parts are identified by the same reference characters throughout the several views.

1 is the rear part of a cylinder of an internal combustion engine and 2 is the rear part of a piston, 3 is. a cylinder head flange attached to the cylinder 1, 4 is a cylinder head attached to the cylinder head flange 3, 5 is a fuel injector attached to the cylinder head 4, and 6 is a receptacle attached to the piston 2.

During, or near the end of, the compression stroke of the piston 2 fuel is injected by suitable means, not forming part of this invention, through the injector 5 in the form of a finely divided spray, the shape of which is as nearly as possible the same as'the shape of the cylinder head 4:. The result is that when the piston passes through the inner dead center the highly compressed air contained in the combustion chamber has been intimately and uniformly mixed with the oil spray, the oil spray has been quickly transformed into oil vapor due to the heat of compression and the heat of the combustion chamber, and the highly explosive charge thus formed is spontaneously ignited at or near the point of maximum compression. Due to the compact shape of the combustion chamber and the absence of all corners or dead spaces not reached by the oil spray the combustion thus obtained is very efficient, but when the best economy is obtained the performance is frequently accompanied by an unpleasant noise, somewhat resembling the noise caused by premature ignitions. As soon as a so-called hot bulb is attached to the cylinder head, either externally or. internally, and so arranged as to receive some fuel oil at each cycle the noise ceases at once but the economy is no longer maintained and the rise in the fuel consumption is dependent upon the size and. position of the hot bulb and the amount of fuel injected into it. The least loss of economy is recorded when the receptacle 6, as shown in the drawings, is attached direct to the piston in line with the oil spray, and when this receptacle is made just large enough to overcome the noise, but no larger, there may then be no loss of economy at all while the operation of the engine is smooth and satisfactory.

I have no absolute explanation to offer for the above phenomenon, but I believe that when the receptacle 6,is used some smouldering exhaust gases are retained in it which, upon the compression stroke of the piston, cause a gradualoommencement of ignition instead of a sudden detonation. The shape of'the receptacle 6 is of paramount importance and a mere flat plate used in its stead has not the same effect. The bottom of the cup is perforated, as at 8, to establish communication with the interior of the cup.

Instead of attaching a separate receptacle 6 to the end of piston 2 a cavity 7 may be formed in the latter and a receptacle 6 inserted as shown in Fig. 2, or a mere flat plate may now be used because the cavity 7 already forms a receptacle.

My invention is applicable to both twocycle and four-cycle engines and may be used in combination with any suitable type of injector. I do not confine my invention to the exact shape of the receptacle shown in the drawings; this may be varied in accordance with the nature of the fuel used.

I claim 1. In an internal combustion engine, a cylinder, a piston reciprocal therein, a head for the cylinder having an opening through which a jet of fuel may be injected, means for injecting a jet of fuel through the opening of the head, and a cup-shaped ignition chamber detachably and reversibly carried by the piston, the bottom of the cup being perforated.

'2. In an internal combustion engine, a cylinder, a piston reciprocal therein, a head for the cylinder having an opening through which a jet of fuel may be injected, means for injecting a (jet of fuel through the open-.

ing of the hea and a cup-shaped ignition chamber having a perforated bottom and secured With its opened end against the 10 piston whereby the perforated end Will be adjacent the opening of the cylinder head.

In testimony whereof I aflix my signature in the presence of two'witnesses.

CHARLES S. SALFELD. Witnesses:

v IRMA D. BREM'ER,

Amer J. MCKERIHAN. 

